The National Institute on Aging (NIA) is launching a nationwide treatment study targeting individuals with mild cognitive impairment (MCI), a condition characterized by a memory deficit, but not dementia. The start-up of the trial, to be announced at a March 15 news conference held in Washington, D.C., coincides with publication of a separate NIA-funded study in this month's issue of Archives of Neurology confirming that MCI is different from both dementia and normal age-related changes in memory. Accurate and early evaluation and treatment of MCI individuals might prevent further cognitive decline, including development of Alzheimer's disease (AD).
The upcoming Memory Impairment Study is the first such AD prevention clinical trial carried out by NIH, and will be conducted at 65-80 medical research institutions located in the United States and Canada. This study will test the usefulness of two drugs to slow or stop the conversion from MCI to AD. The trial will evaluate placebo, vitamin E, and donepezil, an investigational agent approved by the Food and Drug Administration for another use. Vitamin E (alpha-tocopherol) is thought to have antioxidant properties, and was shown in a 1997 study to delay important dementia milestones, such as patients' institutionalization or progression to severe dementia, by about seven months.
Participants will be randomly assigned to one of the three groups. The study will be carried out in 720 people over a 3-year period within the NIA's consortium of AD clinical research centers, called the Alzheimer's Disease Cooperative Study (ADCS). The study will be directed by Dr. Ronald C. Petersen, Ph.D., M.D., of the Mayo Clinic in Rochester, Minnesota, and Dr. Michael Grundman, M.D., M.P.H., of the University of California at San Diego (UCSD). Dr. Leon Thal, M.D., of UCSD directs the ADCS.